What is wrong with my UV image repeating?
As Mr Zak said, it's probably because of a bad unwrapping, some of your UV islands must overlap due to the unwrap method you've chosen, which can be ok in some cases but not if you decide to paint your character, because what you paint on a face will also be painted on another one.

You need to check your UV/Image Editor to understand what happened, typically I guess each of your back faces must fill the whole surface of the texture.

For your purpose the best and easiest way is to first select all the faces of your mesh and U unwrap with the Smart UV Project option: This way you're sure that you've got really distinct islands and none of your face will overlap another one on the UV/Image Editor.



Please select one of your back faces and look what happens, I guess something like this: